private void DeleteStudent_Click(object sender, EventArgs e)
{
ProgressVisibleFalse();
ThemesVisibleFalse();
RegistrationVisibleFalse();
FiltrationVisibleFalse();
int k = listofStudents.SelectedIndex;
if (k > -1)
{
listofStudents.Items.RemoveAt(k);
XmlDocument xDoc = new XmlDocument();
xDoc.Load("users.xml");
XmlElement xRoot = xDoc.DocumentElement;
XmlNode Del;
Del = xRoot.ChildNodes[1];
XmlNodeList node = Del.ChildNodes;
XmlNode a = node[k];
Del.RemoveChild(a);
xDoc.Save("users.xml");
}
}